Development And Application Of Three-tier System

Three-layer architecture becomes new mainstream in the software architecture. Three-layer architecture contains client-layer,logic-layer and data-layer. The client-layer is the software which is used by customer directly. The logic-layer is used to deal with affair and has another name-middle layer.. The data-layer is used to deal with data. This architecture changes the traditional model of Server/Client and become a more efficient solution. Project of my task adopt three-layer architecture. We work out a current application server and protocol which is based on TCP/IP on which we make second-exploiture base. We perform Tonghuajingma sales system. We add much advanced technology in order to enhance capability of server such as data-encrypt, identity- authentication,ASN.l etc. The system use SQLSERVER database as data-layer, Application server use database-connect-pool and SQL language to communicate with SQLSERVER database. The client-layer communicate with server by the session- protocol and express-protocol which is worked out by us. Distributed count is adopted in servers .Every server deal with function-module itself and we use catalog- architecture to ensure data-consistent. We adopt catalog-server in order that client accesses server transparently. The system adopt application server which is performed by us and make us advanced in technology.Keyword: Three-layer architecture;client;server;TCP/IP;Thread pool,Distributed-count,Session-protocol,Express-protocol...